On Monday, Israeli news site Ynet news reported that a Russian "expeditionary force" has arrived in Syria to set up a camp at a government airbase near Damascus in order to conduct air strikes against IS positions.

The report, which cited unnamed Western diplomats, added that “thousands of Russian military personnel are set to touch down in Syria, including advisers, instructors, logistics personnel, technical personnel, members of the aerial protection division, and pilots who will operate the aircraft.”

On Tuesday, RT contacted a military source who also denied Russian troops involvement in Syria.

"There has been no redeployment of Russian combat aircraft to the Syrian Arab Republic,” the source said. “The Russian Air Force is at its permanent bases and carrying out normal troop training and combat duty.”

Earlier media reports suggested that Russia has supplied Syria with Mig 31 fighter jets under a bilateral contract signed in 2007. In August, Turkish media outlet BGNNews.com reported that six jets have landed in Damascus. The report was quickly dismissed by the CEO of the Russian Aircraft Corporation Mig Sergey Korotkov.